This invention relates to interface cards, and more particularly to configuring multiple bus controller cards utilized in a single mass storage unit.
Mass storage units are commonly used in applications where large amounts of data need to be stored. Typically, such mass storage units each contain a number of disk drives connected via a bus, such as a Small Computer System Interface (SCSI) bus that is standard in the art. Such mass storage units typically include one or more bus controller cards to control the bus. Those one or more cards generally connect to a backplane on which the bus is implemented. Bus controller cards may be configured via switches, jumpers or other physical controls on the cards that allow a user to reconfigure the cards as needed.
The configuration of the bus controller cards may depend on their orientation with regard to mating connectors on the backplane. If the bus controller slots are not aligned in the same direction, it may be difficult to configure the bus controller cards properly before or after insertion into the slots, as the user may not understand the proper frame of reference for each card, and may then set the switches, jumpers or other controls incorrectly for one or more bus controller cards.
A bus controller card for a backplane of a mass storage unit detects its position in the backplane, and accordingly manages the relationship between DIP switches on the card and control signals to the card and the backplane.
In one aspect of the invention, a backplane includes two data buses and two slots, each slot having two connectors, where each connector in the slot connects to a different data bus. The slots are adapted to receive two bus controller cards each having two backplane connectors, where the installed orientation of one card is opposite from the other installed card. On a particular bus controller card, each backplane connector is associated with a different data bus, depending on the slot into which the card is inserted.
In another aspect of the invention, each bus controller card has one or more DIP switches controlling certain operational characteristics of the card. After insertion into a slot in the mass storage unit, a card recognizes the data bus connected to each backplane connector via the slot, and defines the relationship between the setting of each switch and control signals relating to the card and the backplane. The DIP switch settings for a card can then remain the same, independent of the particular slot into which the card is inserted. In this way, insertion of bus controller cards in different installed orientations is simplified.
The invention will be more fully understood upon consideration of the detailed description below, taken together with the accompanying drawings.